He said that in addition, rats kept in ordinary laboratory cages before being put into their "enhanced" environment might be considered understimulated prior to the experiment - and therefore not necessarily ideal for comparison with humans.

BBC: Tablets

Personal initiative and responsibility are enhanced in an environment that fosters discussion.

CNN: ASIANOW - TIME Asia

It would be difficult to argue that government polices over the past three years have enhanced confidence in the U.S. business environment.

WSJ: Edward Lazear: The Worst Economic Recovery in History